3D scanners which operate by projecting a patterned probe light onto the scanned object are known from the art, such as the 3Shape TRIOS intra-oral scanner and the ConfoCam C1+ scanning module by Confovis GmbH.
The Confovis technology is based on an illumination unit with a patterned mask having reflective regions defining the pattern. When the mask is exposed from one side with light from one light source a pattern of transmitted light rays propagates from the mask towards the object. When the mask is exposed from the other side with light from another light source, at pattern of light rays reflected from the pattern propagates towards the object. The reflected and the transmitted patterns emerge from opposite parts of the mask such that on the illuminated object they are offset from each other.
One disadvantage of the Confovis design is that two light sources are required for the illumination of the pattern. Further, the Confovis system is not capable of providing a gradual shift between the two patterns.